<?php 
function urlcode($url){
    $url=str_replace(':','3g4j3f6j5d',$url);
    $url=str_replace('/','6g7j9g9m',$url);
    return urlencode($url);
}

function urldicode($url){
   $url=str_replace('3g4j3f6j5d',':',$url);
    $url=str_replace('6g7j9g9m','/',$url);
   return urldecode($url); 
}
?>